1. Field of the Invention
The present invention relates generally to a biosurfactant, a biosurfactant-producing microorganism and their use, particularly, but not by way of limitation, in the enhancement of oil recovery from oil-bearing formations.
2. Description of Prior Art
While use has been made of synthetic surfactant injection into oil formations in attempts to enhance oil recovery, such use has been generally costly and not without problems. Relatively little has been done analogously with biosurfactants.
U.S. Pat. No. 2,413,278, issued to Zobell, discloses a method of facilitating oil recovery by injection of a bacteria of the Desulfovibrio genus into the oil formation. The bacterium is thought to feed upon high molecular weight hydrocarbons and among its beneficial products include surfactants or detergents.
U.S. Pat. No. 2,975,835, issued to Bond, discloses a method for simultaneously fracturing oil-bearing rock and injecting an oil-metabolizing bacterium.
U.S. Pat. No. 3,032,472, issued to Hitzman, discloses a method of facilitating oil recovery from oil-bearing formations by injection of bacterial spores, followed by subsequent induction of spore germination with injection of a nutrient such as molasses. Spores of the Desulfovibrio and Clostridium genera were found particularly suitable.
U.S. Pat. No. 3,340,930, issued to Hitzman, discloses a process of oil recovery involving the injection of numerous petroleum-metabolizing microorganisma. Preformed and/or added surface-active agents cause increased oil recovery.
A recent review of the field of surface-active compounds from microorganisms has been published as Cooper, et al. Surface-active Compounds from Microorganisms. Adv. in Appl. Microbiol. V. 26, pgs. 229 to 253 (1980).